A public land mobile network (PLMN) is a communication network established and operated by a government or an operator authorized by the government for the purpose of providing land mobile communication services for the public. The communication network is generally connected with a public switched telephone network (PSTN), so as to form a communication network on a whole area or country scale. An identifier of the PLMN is generally a string of digital codes, for example, the identifier of the PLMN of China Mobile is 46000, while the identifier of the PLMN of China Unicom is 46001.
With improvements in people's living, more and more users carry terminals (such as mobile phones) when making journeys abroad or having business trips. When a roaming (such as internationally roaming) user is to communicate, his/her terminal should search for a local communication network and access it, so as to enable normal communication. For example, when the terminal moves from a home place to a visited place (e.g., the terminal roams from a home country to a visited country), the terminal should access the PLMN in the currently visited place. However, currently in most cases, after the terminal moves from the home place to the visited place, it often takes a long time (sometimes, even tens of minutes) for the terminal to successfully access the PLMN in the currently visited place, which greatly worsens communication experience of the user.
In some cases, standards of the PLMNs provided by operators of different countries are different from each other. Sometimes, even the standards in a country A may be distinct from the standards supported by an operator b of a country B. Hence, after a subscriber identity module (SIM) card of the operator b of the country B internationally roams to the country A, the communication networks in the country A may not be included in those preferentially searched for, thereby failing to access the communication networks. The communication networks may not be searched for in a full radio access technology (FULL RAT) mode until a “no-service” timer times out.